She also posted a photo of the cake to Instagram and captioned it with "#EatMyS**t" and "#Hypocrisy."

The 27-year-old superstar didn't seem to be looking for a fight, though. She tweeted at the "Fashion Police" host, saying, "I didn't know it was your B-day until this afternoon. Meant as a peace offering. Happy Birthday."

Gaga's feud with the Osbournes dates back years. In 2009, Kelly called Gaga a "butterface" and last year said that Gaga's fans have been telling her to go kill herself. When Gaga responded in a blog post earlier this year, saying Kelly needs to take accountability because she is critical of people on her E! show, Sharon called Gaga a "bully" and a "publicly seeking hypocrite and an attention seeker."

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Quite simply, LeAnne stole Brandi's husband, Eddie Cibrian, and made him her own. Since then, <a href="http://www.foxnews.com/entertainment/2013/02/25/brandi-glanville-opens-up-about-leann-rimes-adrienne-maloof-plastic-surgery-and/">the Real Housewife has been getting her public revenge (book included)</a>, and the feud between the two women just keeps making headlines.